Are you sure your turrets are .262 MOA and not . 262 Inch because .262 x 4 = 1.048 exactly the inch size of 1 MOA at 100 yards ?
If they moved .262 MOA at 100 yards per click then 4 clicks would move 1.0976 inch at 100 yards . You need to explain what you think is your turret difference in less words . Because what I see so far leeds me to believe you have 1/4 minute clicks . I may be miss understanding you .
Shooter can be adjusted to read out in MOA , mils , scope clicks what ever you need . The data like velocity , BC's , sight height , slope range etc etc and Atmospheric data go in and then you make the program read out in what calibartion you need .
Any BC or velocity trimming you do to equal real world dope is a seperate issue to what calibration you choose to match and use on the scope .
What you have to be careful of is that the trimming of velocity or BC to match your real world dope has to be done with the same atmospheric and slope range that you experience on the shooting day otherwise you could just be trimming to equal out differing atmosphere and range conditions .
Under those conditions it will not be as accurate on another day in another place.

The coincidence if the 1.048 correction caught my attention as well, but the tall test for 20MOA/20.9' came in at 22" which calculates to .262. I'm pretty meticulous about setting all the other variables you mention. I'm pretty sure my test is good.

My 0.02 I don't think the only way to make a true chart is too shoot 100 and shoot a max distance and build the chart from that. You have to use the manufacturers B.C. after it goes through a barrel it is different than advertised but consistant. You have to use the graduation on the scope (as long as it's the same it wont matter). If the scope is perfectly level and the zero is perfect at 100 and you check it at 1500 and then adjust the speed your putting into the chart until it matches your 1500 yard marks then everything inbetween will fall into place. I have always had to add speed to make this happen not because it's going fast but because the B.C. was altered by the barrel.

Greyfox, I can not tell what you have going on. But I do believe you are on the right track. The difference between simply adjusting Velocity is it has a different effect across the board. BC, a slightly different effect and stepped BC's sometimes are also needed. When adjusting a turret calibration value, the difference is as you go out farther with a shot you dial more moa. If you have an error in turret calibration and are not spot on .25 moa this error will multiply as you shoot .......
Hope this helps you. It does work for me.

Jeff

Thanks Jeff. That does help. As I have started to shoot at ranges beyond the thousand yard mark I have experienced the same effects and would also like to keep velocity as an actual value, and work with the variables that either have to be corrected or modified for achieving accuracy at the extended ranges. I have been following a lot of your posts about shooting at the extended ranges and was motivated by them to stretch my 1000 yard limit for hunting game. Art

Thanks Jeff. That does help. As I have started to shoot at ranges beyond the thousand yard mark I have experienced the same effects and would also like to keep velocity as an actual value, and work with the variables that either have to be corrected or modified for achieving accuracy at the extended ranges. I have been following a lot of your posts about shooting at the extended ranges and was motivated by them to stretch my 1000 yard limit for hunting game. Art

You are going about it the correct way in my opinion. A good log book with all shots logged that were good hits will be a very useful tool when dialing in the program.
I log,

Distance
Baro psi
Temp
R. Hum.
Shot angle
I always have Spin drift on
And I log coiolis
latitude
and azmuth from a manual compass with degrees.

It is a commitment , takes a little devotion, but will work if you want it to.

i dont think anybody is advocating spray and pray jeff.
i think most of us are interested in taking as few shots as possible.
but its not a perfect world and in hunting situations we have to remember that. here in the east our hills are covered with trees for example. a 1200
yard shot will be dropping thru a canopy of unseen branches. maybe it makes
it and maybe it dosent. a shooter laying on his belly regardless of ability just
might not see what happened. beyond the shooting part there is always the
possibility of animals changing positions while the shooter is recovering from
the last shot or otherwise sidetracked briefly. especially during the rut.
a perfect hit on the wrong animal isnt the nicest thing to be faced with either.
animals change positions all the time. its very important to keep the shooter
aware of which one is the target.
seems to me there is more and more emphasis placed on guns scopes
various programs and individual ability. that is all fine and especially
for those interested in extreme distance shooting at various targets.
live targets however require more than that.
remember this, many of the worlds best long range shooters live right here. most of them hunt long range and they all do it the same way.

Now yobuck, I know you are against technology, and I realize the importance of a good spotter. I was just teasing you a little. Just like you did with me earlier when you followed my post and referred to my methods as bull ****. Right??